2016年12月17日
2016年12月17日托福阅读词汇题：
Thus=therefore
Repetitive=happened many times
Profusely= abundantly
Intentional=planned
Retention=keeping
Elaborated= developed
Still=motionless
Inexplicably
Consistent
2016年12月17日托福阅读真题第一篇：
题材划分：农业发展史
主要内容：亚马逊农业耕作
先讲亚马逊的土地不适合耕作。后来讲到亚马逊开始发展农业的原因。由于当地人口密集，不能完全靠swindle理论解释，于是引出了亚马逊农业发达的原因，就是洪水使riverbank沉淀，sediment所以土地非常得fertile;农民有方法来改善土地质量，往里面添加很多成分以确保土地中营养物质留存;农民们有计划地进行耕作，选择性种植valuable corps，并且把种子distribute创收制造产。
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TPO-21 The Origins of Agriculture
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Seasonal floods excavate and redistribute nutrient-rich silt onto beaches and islands, enabling dry-season riverside agriculture of rice, beans, and corn on the river's shoreline without the addition of fertilizer, with additional slash and burn agriculture on higher floodplains. Fishing provides additional food year round, and free-range chickens need little or no food beyond what they can forage locally. Charcoal made largely from forest and shoreline deadfall is produced for use in urban areas. Exploitation of bush meat, particularly deer and turtles is common.
Deforestation [citation needed]and increased road-building bring human encroachment upon wild areas, increased resource extraction and threats to biodiversity.
Extensive deforestation, particularly in Brazil, is leading to the extinction of known and unknown species, reducing biological diversity and adversely impacting soil, water, and air quality. A final part of the deforestation process is the large-scale production of charcoal for industrial processes such as steel manufacturing. Soils within the region are generally shallow and cannot be used for more than a few seasons without the addition of imported fertilizers and chemicals.
2016年12月17日托福阅读真题第二篇
题材划分：动物类
主要内容：鸟类飞行的起源。
主要讲解了鸟类飞行的起源和羽毛功能研究。全文分四段，先讲发现一种恐龙化石Archaeopteryx，然后研究在鸟可不可以通过flip来飞行，产生分歧。第二段说其实羽毛最初出现是为了提供剧烈肌肉运动中需要的热能，这为之后飞行提供了基础。第三段介绍对羽毛的第一种解释，Tree Theory认为鸟龙之前住在树上，热量使它们能够从树间进行远距离移动。第四段提出Warm Theory 认为羽毛维持体温，鸟龙好像是温血动物，能比冷血动物在追捕猎物移动更久。
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Most birds can fly, which distinguishes them from almost all other vertebrate classes. Flight is the primary means of locomotion for most bird species and is used for breeding, feeding, and predator avoidance and escape. Birds have various adaptations for flight, including a lightweight skeleton, two large flight muscles, the pectoralis (which accounts for 15% of the total mass of the bird) and the supracoracoideus, as well as a modified forelimb (wing) that serves as an aerofoil. Wing shape and size generally determine a bird species' type of flight; many birds combine powered, flapping flight with less energy-intensive soaring flight. About 60 extant bird species are flightless, as were many extinct birds. Flightlessness often arises in birds on isolated islands, probably due to limited resources and the absence of land predators. Though flightless, penguins use similar musculature and movements to "fly" through the water, as do auks, shearwaters and dippers.
2016年12月17日托福阅读真题第三篇
题材划分：地质类
主要内容：溪流和沉淀物
主要讲了stream和sediment。先说了stream下了定义，然后说水流沉淀的三种方式，分别是solution, suspension和river bed。然后每种都有解释，第一种溶解，水里有各种矿物质什么的。第二种并不是所有东西都溶解，要看particle。小的流速快跟着河流就走了，大的可能在水里跳就讲到横向水流流速和颗粒质量导致沉淀速度，于是会出现有suspended 的情况。另外河流的流速和携带沉淀物的能力没有直接的关系，说沉淀物的大小和类型取决于水流的速度 和沉积的速度，第三种bed不易观察因为它是地下水会穿过河床下面，穿过石孔在流。最后说无论是固定的沉淀物还是悬浮的沉淀物其实都是移动的。最后考了suspension 和 river bed 的表格题。
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Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice, and/or by the force of gravity acting on the particles. For example, sand and silt can be carried in suspension in river water and on reaching the sea be deposited by sedimentation and if buried this may eventually become sandstone and siltstone, ( sedimentary rocks).
Sediments are most often transported by water (fluvial processes), but also wind (aeolian processes) and glaciers. Beach sands and river channel deposits are examples of fluvial transport and deposition, though sediment also often settles out of slow-moving or standing water in lakes and oceans. Desert sand dunes and loess are examples of aeolian transport and deposition. Glacial moraine deposits and till are ice-transported sediments.